AL–amyloidosis in patient with myeloma. A case report.

Introduction.
AL- amyloid deposits in various tissues form a β-pleated sheet structure. Amyloidosis (A.) is caused mainly by plasma cell neoplasm which secretes abnormal immunoglobulin mainly light chains. Disease is characterized by abnormal presence of fibrillary proteins in one or more organs' extracellular spaces, causing structural and functional organ damage (S.H. Swerdlow et al., 2008). Around 20% of A. patients have plasma cell myeloma. Myeloma is also rare pathology of hematopoietic system in the world and in Latvia (5 cases per 100000 inhabitants - S.Lejniece, 2012; S.Pildava, 2012). AL- amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin light chains (κappa:lambda =1:4) usually secreted by a small plasma cell clone.
The average age of diagnosed patients is 65 years and less than 10% of patients are under 50. (Desport E. et al., 2012). The disease is caused when immunocompetent cells (lymphocytes or plasma cells) do not function properly and produce abnormal protein. These light chains come together to form amyloid deposits in different organs which can cause serious damage of kidneys, heart, liver, gastrointestinal tract, soft tissues, peripheral nerves etc. About 10% to 15% of patients with multiple myeloma may develop overt AL amyloidosis and may lead to fatal hepatic failure (R. Ketsueki, S.Tabata S.et al., 2012).
The aim of the presentation is to demonstrate rare pathology of liver in patient with myeloma on biopsy material.
Methods.
Liver biopsy was examined with: routine haematoxylin and eosin, Periodic acid-Schiff (PAS), Masson-Trichrome, Giemsa, Gordon reticulin method, Congo-red. Immunohistochemistry staining was done with such antibodies: kappa, lambda, CD138, CD20, LCA, CD45. Our results were compared with Pub med publications.
Results. 51 year old female was hospitalized at Riga East Clinical University Hospital’s Infectology Center of Latvia with thoracalgia, mediastinal pressure feeling and hepatomegaly. Hyperproteinemia was 128 g/l; liver injury tests: ALAT-34 U/l, ASAT-72 U/l. Laboratory tests for hepatitis C and B were negative; Paraproteinemia (IgG, kappa) - 54 g/l. Skull x-ray showed osteolytic lesions in frontal and parietal bones.
In livers biopsy: parenchimal and stromal histological architecture is totally destructed. Pail eosinophilic, Congo red-positive amyloid as larges patches was found in hepatic lobular and preriportal areas. Masive subsinusoidal amyloid deposits affect hepatocytes structure. We can find just some saved groups of hepatocytes from 1-10 small atrophic cells with amorphic cytoplasm, Congo-red positive inclusions and sametimes without nuclei. Amyloid deposits were kappa - weakly positive and lambda – negative; CD138 marker for plasma cell was (-) in liver tissues.
After some time we have got bone marrow trepanbiopsy which was characterized by hypercellulary of bone marrow (75-90%). It was subtotally replaced by plasma cells. Small size plasma cells (CD138+, 50-75%) they have round or oval hyperchromic nuclei, some cells - small nucleoli and have high nuclear/cytoplasmatic ratio (5-7:1). Plasma cells immunphenotype was: CD138+, Kappa+. Labda-, LCA-/+, CD20-. Hypoplasia of myelopoietic (M) and erythropoietic (E) cells was proved. Ratio was M/E-3:1.There was detected some small hypolobulated megacaryiocytes (0-2 cells hpf) and diffuse low grade reticular fibrosis.
Conclusions.
The case demonstrates how diagnosis of haematological malignancy was made with the help of detection of its complication: AL-amyloidosis. As liver amyloidosis is rare pathology (9 cases/per 1000000/per year) we wanted to pay doctors' attention to this complication of myeloma from our practice. Prognosis of both pathologies depends on the early correct diagnosis and specific treatment.